Humidifier

ABSTRACT

Apparatus for humidifying air by rotating evaporative material supported within a water reservoir while flowing air through the material. A baffle in the upper portion of the humidifier separates an air inlet opening from an air outlet opening. The air introduced into the humidifier at the air inlet opening is directed by the baffle from the top of the humidifier through the evaporative material and out the air outlet opening.

United States Patent [72] Inventor William P. Paulln Barrie, Ontario,Canada [21] App]. No. 763,520 [22] Filed Sept. 30, 1968 [45] PatentedOct. 5, 1971 [73] Assignee Canadian General Electric Company LimitedToronto, Ontario, Canada [54] HUMlDlFIER 9 Claims, 4 Drawing Figs.

[52] U.S. Cl 261/30, 261/92, 55/234, 55/400, 55/473 [51] 1nt.C1 F24f3/14[50] Field otSearch 261/83, 84, 30, 92, 72; 55/234, 400, 473

[56] References Cited UNITED STATES PATENTS 1,961,508 6/1934 Persons i.261/92 2,432,755 12/1947 Hanson 261/92 2,875,846 3/1959 Yonkers 55/3543,274,993 9/1966 Martin 261/92 3,352,297 11/1967 Martin et 261/923,474,598 10/1969 Keuls 261/92 3,480,209 11/1969 Stilesm. 261/922,584,618 2/1952 Robic 261/92 Primary Examiner Frank W. Lutter AssistantExaminer-Bernard Nozick Attorneys-Lawrence R. Kempton, Leonard Jv Plait,

Frederick P. Weidner, Jr., Frank L. Neuhauser, Oscar B. Waddell andMelvin M. Goldenberg ABSTRACT: Apparatus for humidifying air by rotatingevaporative material supported within a water reservoir while flowingair through the material. A baffle in the upper portion of thehumidifier separates an air inlet opening from an air outlet opening.The air introduced into the humidifier at the air inlet opening isdirected by the baffle from the top of the humidifier through theevaporative material and out the air outlet opening,

THE; 1 (1.55238 PATENTED mm 5 :97:

SHEET 1 UF 2 dun-42g Attorney PATENTEDUBI Si n sumaurz IN V/iN'lh/z, W1lll'am F? Paulin Attorhgy IIUMIDIFIER BACKGROUND OF THE INVENTION Thisinvention relates to humidifiers and in particular to portablehumidifiers for use in the home.

In some of such humidifiers, air is passed directly through a wettedevaporative material in order to effect transfer of the moisture to theair. Usually, the material is in the shape of a drum or a belt having aportion thereof submerged in a water reservoir so that as the drum orbelt moves, it is wetted. The drums and belts now are mostly made of afoam plastic.

One difficulty in the design of such humidifiers is to construct drumsand belts wherein the foam plastic provides an optimum evaporationsurface area but a minimum restriction of the airflow therethrough sothat a maximum amount of moisture is added to the airflow. Anotherdifficulty in the design of humidifiers intended for use over longperiods of time is the handling of the mineral deposits particularlylime particles which remain behind on the wetted evaporative materialwhen the water is evaporated therefrom. Unless the water is distilled,these deposits will always be present thus requiring frequent cleaningin order to sustain efficient operation of the humidifier. This and alsothe growth of odor producing organisms in the water and on the wettedevaporative material makes the maintenance of this type of humidifierunpleasant and difficult for the consumer.

SUMMARY OF THE INVENTION In accordance with the present invention, thereis provided a portable humidifier comprising a housing including top,side, front and rear walls. A water-filled reservoir occupies the lowerportion of this housing from which it may be removed in the manner of adrawer. An evaporative material preferably in the form of a drum isrotatably supported within the reservoir and partially submerged in thewater therein. Air inlet and air outlet openings provided in the upperportion of the housing are separated by a baffle means which extendsfrom the top wall of the housing downwardly towards the evaporativematerial supported within the water reservoir and terminates short of itthereby dividing the upper portion of the housing into two compartments.Drive means are located in one of the compartments for rotating theevaporative material and providing an air flow from the air inletopening through the evaporative material to the air outlet opening.

It is an object of this invention to provide a high efficiency, portablehumidifier which utilizes as the wetted evaporative material a plasticfoam preferably formed into a drum which can easily be removed from thehumidifier for cleaning purposes without the use of tools.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective rear view ofthe new humidifier with the water reservoir partially pulled out;

FIG. 2 is a perspective view of the drive and baffle means whereby thehumidifier housing is omitted and the baffle means partially cut away toexpose the drive means;

FIG. 3 is an enlarged, partial view in the direction indicated by arrowA of FIG. 2, and

FIG. 4 is a schematic side view into the interior of the humidifier.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, thereis shown a humidifier cabinet or housing from the rear thereby exposingrear wall 11, sidewall I2 and top wall 13. Housing 10 is preferablyrectangular in shape but can be given other shapes if so desired. Therear wall II covers only the upper portion of housing 10 thereby leavingan opening in the lower portion for inserting or withdrawing a waterreservoir I4 in the form of a drawer. In order to facilitate thesemovements, a handle I5 is provided preferably along the top edge of rearwall 16 of water reservoir 14. Evaporative material in the form of acylinder or drum 17 is rotatably supported within water reservoir 14 bya roller 18 secured in the end walls of water reservoir I4 as seen at19. Drum 17 and roller 18 extend substantially through the entire lengthof water reservoir I4 and form a unit with the reservoir which may bereadily withdrawn from and returned into housing 10.

Drum 17 consists of a supporting layer 20 made of a netted plasticmaterial which is covered by a layer of foam plastic 2I such aspolyurethane foam. Two clamping strips 22 and 23 secure layer 21 tosupporting layer 20. Roller I8 is also made of a plastic material. Anair inlet opening 24 preferably of circular shape is provided in rearwall 11 and covered by a screen plate 25. An air outlet opening 26occupies the major part of top wall 13 and is covered by louvers 27, 28and 29. The louvers are provided with fixed slanting vanes andpreferably are of a square shape so that they can be inserted into theair outlet opening in four different positions. This makes it possibleto change the direction of the airflow emitting from the humidifier asrequired. In the remaining part of top wall I3, a water level indicator30 is located which indicates the amount of water in reservoir 14. Afloat mechanism may be used for this purpose which extends into thereservoir and may be retracted therefrom by a handle 3|. Several switchbuttons 32 are also located on top wall 13 for controlling theelectrical system of the humidifier. Electrical conductor 33 is used toconnect the humidifier with a source of electrical energy.

FIG. 2 illustrates the arrangement and function of the baffle and drivemeans within the upper portion of housing 10. A baffle 34 in the form ofa box with an open bottom and an air passage opposite the air inletopening 24 extends from the top of housing It] downwards towardevaporator drum 17 and terminates short of it. The baffle 34 divides theupper portion of housing 10 into two compartments extending across thewidth of said housing thereby separating air inlet opening 24 from airoutlet opening 26. The compartment with air inlet opening 24 housesdrive means which is secured to baffle 34. The drive means includes anelectric motor 35 driving a fan propeller 36 arranged in the air passageprovided by air inlet opening 24. Motor 35 is provided with a rear shaftextension 37 which is coupled to a speed reducing gear 38, for instance,a worm gear. Speed reducing gear 38 in turn drives over a shaft 39connected thereto by a flexible rubber coupling 39a, and a frictiondrive pinion 40 a drive roller 41. Shaft 39 extends thereby from thespeed reducing gear 38 in a downwardly slanting direction towards oneend wall of boxlike baffle 34 and is rotatably secured therein.

Pinion 40 presses against a bevelled end portion 42 of drive roller 41,which is also rotatably secured in the end walls of baffle 34. Roller 41covered with a resilient material presses against the evaporator drum I7and causes it to rotate. Seen also in this FIG. is float 43 of the waterlevel indicator in its retracted, inactive position from which it may betilted into reservoir 14 about an axis of rotation 44 by handle 31(shown in FIG. 1). This water level indicator is not part of thisinvention but is the subject matter of a copending U.S. Pat. applicationSer. No. 763,837 of T. Ridding filed Sept. 30, 1968, now U.S. Pat. No.3,536,032 and assigned to the same assignee as the present application.

In order to insure a proper function of the drive means at all times,several biasing means have been provided and are illustrated in FIG. 3.A leaf spring 45 secured to an end wall of baffle 34 and acting on thebearing of shaft 39 exerts a downward pressure on this shaft so thatfriction drive pinion 40 is kept in proper contact with the bevelled endportion 42 of drive roller 41. Similarly, a U-shaped spring 46 isconnected with one leg 47 in a horizontal position to one end wall ofbaffle 34 so that the other leg 48 projects into the lower portion ofthe humidifier also in a horizontal position. The free end of leg 48 isslightly curved downwards so that when water reservoir I4 is pushed backinto the humidifier housing I0, axle 19 of roller 18 may slide up thecurved portion onto leg 48. As roller axle 19 is located in a verticallyextending slot 49 in the end wall of reservoir 14, spring 46 exerts apressure on roller 18 in the upward direction. The same biasing meansis, of course, provided on the other end of roller 18, and therefore,drum 17 supported by roller 18 is constantly and evenly pressed againstdrive roller 41.

An alternative of this arrangement would be to secure supporting roller18 in a normal, not slidable way in the end walls of reservoir 14 andemploy a floating bearing at each end of drive roller 41. The floatingbearings allow the drive roller 41 which may be filled with sand, tomove up and down and maintain even pressure on drum 17 regardless of anydeformation of the drum from a truly circular shape. The flexible rubbercoupling 390 between drive shaft 39 and reducing gear 38 and therotatable securing of drive shaft 39 and drive roller 41 to the floatingbearing plate in the end wall of baffle 34 facilitate the up and downmovement ofdrive roller 41. Pinion 40 and bevelled end 42 of driveroller 41 are still biased together as mentioned before but here thebiasing spring would be mounted on the floating bearing plate. Finally,by allowing the opposite end of drive roller 41 to move up and down in akeyhole-shaped slot, the drive roller is removable by raising the endand urging it laterally into the enlarged portion of the slot wherebythe other end becomes disengaged from the bearing plate and the rollermay be withdrawn. Since this can be done without the use of a tool, itconstitutes a major advantage of this arrangement.

In operation, the humidifier works as schematically indicated in FIG. 4.Motor 35 drives fan propeller 36 which draws air through air inletopening 24 into housing 10. The air is ducted downwards by baffle means34 and forced twice through the wetted surface of drum l7. Thereby, theair picks up moisture and is then ducted upwards and discharged throughthe louvers covering air outlet opening 26. Motor 35 actuates driveroller 41 through reduction gear 38 and shaft 39. Drive roller 41 whichis coated with a resilient material presses against drum l7 and causesit to rotate at a predetermined speed. The rotation of drum 17 throughthe water in reservoir 14 traps droplets of water in the foam plastic 2|(FIG. 1) which are drawn up into the airflow produced by fan propeller36 and evaporated. The speed of rotation of fan propeller and drum maybe controlled by reducing the voltage applied to the motor by means of atapped reactor inserted in series circuit relation with the motor. Theamount of reactance is selected by actuating one of the buttons 32 (FIG.I) of a tap switch which provide high, medium and low positions and alsoan "off position." As the schematic view of FIG. 4 further shows, thedrive roller 41 is positioned above and slightly to the rear ofsupporting roller 18. This and their vertical separation distance may bechosen so that drum 17 is urged toward the front of reservoir 14 andretained there. This provides an adequate space between drum l7 and thebackwall of reservoir 14 into which the before-mentioned float 43 (FIG.2) of a water level indication means may be lowered for indicating thewater level on indicator 30 (FIG. 1) on top of the humidifier cabinet10. The float 43 may also be used for actuating a water level switchwhich turns the unit off automatically when the level is reduced to apredetermined amount. Finally, as indicated, the direction of rotationof the drum is chosen so that it does not tend to climb up the frontwall of the reservoir which otherwise would result in the drum ceasingto rotate.

The design of the described humidifier includes many advantages andimprovements in operating convenience and performance. The basicarrangement of the three major subassemblies, the housing, the drive andbaffle assembly and the reservoir and drum assembly provides an easy andsimple way for withdrawing of the reservoir and drum assembly from theunit for the purpose of refilling the reservoir and cleaning of thedrum. Of course, the refilling of the water reservoir alone could easilybe achieved without withdrawing of the water reservoir from thehumidifier housing by simply providing a funnel inside the housing belowone of the louvers covering the air outlet opening. In such event, thefunnel, preferably made of a plastic material could be mounted on thefront wall of the humidifier housing immediately beneath, for instance,the middle louver. Upon removal of this louver water can then be pouredinto the funnel which will guide it to the reservoir. A look at FIG. 4reveals how easily this can be done.

The drum itself is made of a foam plastic layer supported by a cylinderof netted plastic material. This keeps the plastic foam dilated andpermits the use of a thin layer of plastic foam which in turn does notimpede the airflow to the extent that would occur if the plastic foamwere self-supporting. The plastic foam layer is also readily removablewhich is very important since the accumulation of lime particles on theplastic foam will eventually impede the airflow so that periodiccleaning is required. The design of the drum makes it easy for thecustomer to unfasten the plastic foam layer from the cylindrical nettedplastic material by removing the clamping strips and then simply pullingit off the cylinder. The foam plastic layer may then be washed in aconventional manner. Finally, there is a minimum of mechanical stress onthe foam plastic layer during the rotation of the drum. The foam plasticlayer is rolled together with the supporting cylinder between the driveand supporting roller and the very small tangential driving force isdistributed over the full length of the plastic foam cover.

The manner in which the drum is rotated between a resilient surfacedupper or drive roller and a lower or supporting roller results in asignificant reduction in the tendency for lime residue to adhere to thefoam plastic layer. The gentle squeezing action of the rollers loosensparticles of lime adhering to the foam plastic layer and as the drumcirculates through the water, the particles are flushed off and settleto the bottom of the reservoir. It is to be noted that the cleaningaction is distributed over the full length of the drum so thatsubstantially the entire surface of the plastic foam layer is cleaned.

The proper orientation of the drum in the reservoir is essential ifsmooth rotation is to be achieved. With the drive and supporting rollerslocated at the top of the drum, friction between the ends of the drumand the end walls of the tank will cause the drum to skew and may causejamming. If, how ever, the friction is restricted to the top portion ofthe drum ends, skewing does not occur and for this reason the walls ofthe reservoir are formed inwards at their top ends (FIG. 1) to provide asufficient clearance between the ends of the drum and the end walls ofthe reservoir in the critical areas. The contours achieved with thisinward forming also provide smooth guides to keep the drum located inthe proper posi tion.

The use of bacteriacides to control the growth of odorproducing bacteriain water reservoirs of humidifiers is well known. These materials rangefrom common borax to blends of quaternary ammonium compounds. With theuse of the latter which are the most effective types of bacteriacide forthis application, the occurrence of foaming of the water in thereservoir causes the pores of the plastic foam layer to becomeobstructed and thereby impedes the airflow through the evaporativematerial. Such a reduction of airflow is undesirable because it reducesthe evaporative output of the humidifier and also increases the pressuredrop in the air flow and thereby increases the audible noise in thesystem. This foaming may be eliminated by adding antifoaming agents tothe water in the appropriate amounts and the silicone emulsion type hasbeen found to be particularly effective in this regard.

The foregoing is a description of the preferred embodiment of theinvention, and variations may be made thereto without departing from thespirit of the invention, as defined in the appended claims.

What is claimed is:

l. A portable humidifier comprising a housing including top, side, frontand rear walls, a drawer water reservoir occupying the lower portion ofsaid housing, an evaporative material of porous annular form rotatablysupported within said reservoir on a support roller secured to saidreservoir, said reservoir and evaporative material being readilyremovable as a unit from and returned to the housing, air inlet andoutlet openings in the upper portion of said housing, baffle meanswithin the upper portion of the housing extending from the topdownwardly towards the evaporative material within said reservoir andterminating short of it, said baffle means dividing the housing into twocompartments and separating the air inlet opening from the air outletopening, a fan propeller, mounted in the housing and drive meansincluding an electric motor located in one of said compartments and arear shaft extending from the electric motor and coupled to a gearreduction means, said rear shalt in turn drives a drive roller rotatablysecured to said baffle means, said drive roller being mounted adjacentthe evaporative material and pressing against the outer surface of saidevaporative material, said motor being connected for both driving saiddrive roller and the fan propeller whereby the evaporative material isrotated and an airflow is produced from the air inlet opening throughthe evaporative material to the air outlet opening.

2. A portable humidifier as defined in claim 1 wherein the supportingroller is secured in vertically extending slots provided in the endwalls of the reservoir and spring means exert a biasing pressure to thesupporting roller in the upward direction.

3. A portable humidifier as defined in claim 2 wherein said drive rolleris secured to said baffle means in a floating bearing so as to permit anup and down movement ofsaid roller.

4. A portable humidifier as defined in claim 1 wherein the air inletopening is located in the rear wall and the air outlet opening in thetop wall of said housing.

5. A portable humidifier as defined in claim 4 wherein the baffle meansforms an open-bottomed box provided with an air passage opening inalignment with said air inlet opening.

6. A portable humidifier as defined in claim 1 wherein the evaporativematerial is a continuous web in the shape of a drum and said driveroller is provided with a resilient surface and extends along the fulllength of said drum in a substantially parallel spaced relationship tothe axis of the drum.

7. A portable humidifier as defined in claim 6 wherein the drum-shapedevaporative material consists of a supporting layer made of a nettedplastic material covered by a layer of foam plastic and secured theretoby clamping strips.

8. A portable humidifier as defined in claim 6 wherein said drive rolleris positioned above and slightly to the rear of the roller supportingthe drum within the water reservoir.

9. A portable humidifier as defined in claim 6 wherein the top ends ofthe walls of the reservoir are formed inwards to provide a guidingaction and clearance for the evaporator drum.

1. A portable humidifier comprising a housing including top, side, frontand rear walls, a drawer water reservoir occupying the lower portion ofsaid housing, an evaporative material of porous annular form rotatablysupported within said reservoir on a support roller secured to saidreservoir, said reservoir and evaporative material being readilyremovable as a unit from and returned to the housing, air inlet andoutlet openings in the upper portion of said housing, baffle meanswithin the upper portion of the housing extending from the topdownwardly towards the evaporative material within said reservoir andterminating short of it, said baffle means dividing the housing into twocompartments and separating the air inlet opening from the air outletopening, a fan propeller, mounted in the housing and drive meansincluding an electric motor located in one of said compartments and arear shaft extending from the electric motor and coupled to a gearreduction means, said rear shaft in turn drives a drive roller rotatablysecured to said baffle means, said drive roller being mounted adjacentthe evaporative material and pressing against the outer surface of saidevaporative material, said motor being connected for both driving saiddrive roller and the fan propeller whereby the evaporative material isrotated and an airflow is produced from the air inlet opening throughthe evaporative material to the air outlet opening.
 2. A portablehumidifier as defined in claim 1 wherein the supporting roller issecured in vertically extending slots provided in the end walls of thereservoir and spring means exert a biasing pressure to the supportingroller in the upward direction.
 3. A portable humidifier as defined inclaim 2 wherein said drive roller is secured to said baffle means in afloating bearing so as to permit an up and down movement of said roller.4. A portable humidifier as defined in claim 1 wherein the air inletopening is located in the rear wall and the air outlet opening in thetop wall of said housing.
 5. A portable humidifier as defined in claim 4wherein the baffle means forms an open-bottomed box provided with an airpassage opening in alignment with said air inlet opening.
 6. A portablehumidifier as defined in claim 1 wherein the evaporative Material is acontinuous web in the shape of a drum and said drive roller is providedwith a resilient surface and extends along the full length of said drumin a substantially parallel spaced relationship to the axis of the drum.7. A portable humidifier as defined in claim 6 wherein the drum-shapedevaporative material consists of a supporting layer made of a nettedplastic material covered by a layer of foam plastic and secured theretoby clamping strips.
 8. A portable humidifier as defined in claim 6wherein said drive roller is positioned above and slightly to the rearof the roller supporting the drum within the water reservoir.
 9. Aportable humidifier as defined in claim 6 wherein the top ends of thewalls of the reservoir are formed inwards to provide a guiding actionand clearance for the evaporator drum.